just like wikipedia... where people can screw it up, then you have to spend time fixing it. and if its subtle, people may be getting the wrong information until fixed. etc.

edit - although, if this wikipost is always a "2nd" post after the stickied post(s) that does kind of become an "optional" thing for wiki people to use and cynics like me can ignore at first sign of trouble. clearly im not talking about it being done automatically in every thread. that would be...

as you can see im a cynic.

personally, i think forums avoid anything negative, because its posts (and poster/postcount/etc), there is discussion, and moderators are posters who can see post [edit] histories and IP addresses.